The problem with any type of physical barrier however is whether it can deal
with spatial and temporal variability in the physical environment. Fish
behave very differently in areas with varying sizes and types of cover, and
during hydrographic peaks. We found that gobies showed significant
improvement in station-holding abilities with a subtle increase in substrate
size (from smooth to sandy). Freshets and floods would certainly reduce
efficacy of barriers. Developing a barrier that is effective under a normal
range of conditions in a single stream is definitely a challenge.
[Personal and un-scientific observation - I still have several of those
round gobies left from our research. They live in a large fiberglass tank,
are quite tame, and are used frequently for educational purposes. They eat
trout chow, shrimp chunks, bloodworms, almost anything. Life, after their
brief career as professional swimmers, has been good.]
>>>Today's Chicago Tribune carries an article on efforts to contain the
goby,
brought over in ballast tanks from Russian waters, which has widely infested
stretches of the Great Lakes. A 1.3 million dollar electric barrier is
planned across the Chicago Sanitary & Ship Canal which connects Lake
Michigan with the Des Plaines River in the Illinois River flowage....
Scott<<<
>>> The Army Corps of Engineers were planning to build a barrier in
some canal some time ago. But, by the time they got around to it, the
gobies had spread beyond that area. (I seem to recall a post on this list
with that info).
Sajjad<<<
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